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The collimation of an SCT can be a daunting task for a beginner, but it is an absolutely necessary process to get the most out of your telescope! Doing the collimation with the factory Phillips screws is certainly doable, but requires a lot of back and forth between the eyepiece and the secondary mirror. You also need to work, in the dark, close to the corrector plate with a sharp metal screwdriver, requiring a lot of concentration and precision in your movements.

By replacing the factory Phillips collimation screws of your Celestron 6" with a set of Bob's Knobs collimation thumbscrew, you can make the process of collimation an effortless and risk-free task. Simply grab a Bob's Knobs thumbscrew and turn!

The factory dust cover will usually fit properly with Bob’s Knobs installed, except on some very early versions.

Fits: Celestron 6" (15 cm) f/10 SCT versions (C6-A-XLT, C6-GT, C6-S, C6-SE, C6-SGT, others)

Knobs: Black oxide steel (black) or stainless steel (silver), 12 mm (1/2”) diameter
Threads: Black oxide or stainless steel. Due to the Canadian weather, we, David Astro, decided to only offer the slightly more expensive, but more durable stainless steel Bob's Knobs.